Success with Meringue!

i made my Mom's Meringue cookies for the first time last night, and would you believe it, they were a success!

but i think i got lucky. however, i've also been told there are certain things you should never do when making a meringue. Such as use a metal bowl, or metal utensils. I used a glass bowl, but my hand mixer has metal attachments. and then i used a plastic spoon to make the drop cookies.

Metal bowl not OK? plastic bowls not OK? metal mixer OK? plastic spatula/other utensils OK for meringues? What else should I know for next time?